Patent US6349207B1 successfully refreshed from Google Patents.
US6349207B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for analyzing interference in a cellular radiocommunication system
Assignee: Thales SA
•
Filing: 1998-07-10
•
Granted: 2002-02-19
•
Expires: 2018-07-10
Abstract
Abstract A system for analyzing interference caused by neighboring cells in a cellular communication system. A multipath synchronization is performed on the learning sequences of the beacon frequencies in order to determine the number of base stations using the analysis frequency as a beacon frequency. The identifiers of the base stations which are transmitting the beacon frequencies on which a synchronization has been made are demodulated after spatial filtering. A multipath synchronization is performed on learning sequences of the traffic frequencies so as to determine the number of base stations using the analysis frequency as a traffic frequency.
Inventors
- 👤 Jean-Jacques Monot
- 👤 Francois Pipon
- 👤 Frédérique Lasnier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:33
CPC Classifications
H; H04; H04W; H04W16/00; H04W16/18
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
121 words
A method of analyzing interference in a cellular radio communication system including beacon frequencies and traffic frequencies such that the method, to search on a specified analysis frequency and inside a cell for an origin of interference caused by neighboring cells, comprises: performing a multipath synchronization on learning sequences of the beacon frequencies so as to determine a number of base stations using the specified analysis frequency as a beacon frequency; demodulating, after spatial filtering, identifiers of the base stations transmitting the beacon frequencies on which a synchronization has been made; and performing a multipath synchronization on learning sequences of the traffic frequencies so as to determine a number of base stations using the specified analysis frequency as a traffic frequency.
Claim 2
Independent Claim
121 words
A method of analyzing interference in a cellular radio communication system including beacon frequencies and traffic frequencies such that the method, to search on a specified analysis frequency and inside a cell for an origin of interference caused by neighboring cells, comprises: performing a multipath synchronization on learning sequences of the beacon frequencies so as to determine a number of base stations using the specified analysis frequency as a beacon frequency; demodulating, after spatial filtering, identifiers of the base stations transmitting the beacon frequencies on which a synchronization has been made; and performing a multipath synchronization on learning sequences of the traffic frequencies so as to determine a number of base stations using the specified analysis frequency as a traffic frequency.
Claim 3
Dependent Claim
85 words
The method according to claim 1 , further comprising: determining identifiers of the base stations using the specified analysis frequency as the traffic frequency by: searching a set of frequencies of a network for the base stations which have a beacon frequency synchronous with the traffic frequency, demodulating results of the searching step after spatial filtering so as to obtain beacon frequencies and identities of the base stations; and preserving that which includes the specified analysis frequency from among the list of demodulated traffic frequencies.
Claim 4
Dependent Claim
177 words
The method according to claim 2 , wherein to perform the multipath synchronization on the learning sequences associated with the beacon or traffic frequencies in the presence of jammers, the method comprises: estimating a correlation matrix {circumflex over (R)} xx −1 of signals received on a set of N sensors; calculating an inverse correlation matrix {circumflex over (R)} xx 1 in calculating cross-correlation vectors {circumflex over (r)} xd + between signals X (k) received on the set of N sensors and a known learning signal d(n); calculating a multiplier synchronization criterion by taking a scalar product of the cross-correlation vector {circumflex over (r)} xd −1 and a vector obtained from a product of the inverse of the correlation matrix {circumflex over (R)} xx −1 and a transposed conjugate cross-correlation vector {circumflex over (r)} xd + ; and comparing a value of the criterion obtained with a threshold value η determined so as to place a synchronization on a sample (P) of the signal for which the value of the criterion exceeds the value of the threshold η.
Claim 5
Dependent Claim
81 words
The method according to claim 2 , wherein on a beacon frequency the demodulation of the signaling messages indicating the associated traffic frequencies and the identity of the base station is obtained by spatial filtering implemented by utilizing the learning sequence of the beacon frequency to modify a reception diagram and separate various signals received by forming reception holes in a direction of the jamming signals produced by other base stations and jammers external to a network of the base stations.
Claim 6
Dependent Claim
174 words
The method according to claim 1 , wherein to perform the multipath synchronization on the learning sequences associated with the beacon or traffic frequencies in the presence of jammers, the method comprises: estimating a correlation matrix {circumflex over (R)} xx of signals received on a set of N sensors, calculating an inverse correlation matrix {circumflex over (R)} xx −1 in calculating cross-correlation vectors {circumflex over (r)} xd between signals X (k) received on the set of N sensors and a known learning signal d(n); calculating a multiplier synchronization criterion by taking a scalar product of the cross-correlation vector {circumflex over (R)} xd and a vector obtained from a product of the inverse of the correlation matrix {circumflex over (R)} xx −1 and a transposed conjugate cross-correlation vector {circumflex over (r)} xd + ; and comparing a value of the criterion obtained with a threshold value η determined so as to place a synchronization on a sample (P) of the signal for which the value of the criterion exceeds the value of the threshold η.
Claim 7
Dependent Claim
29 words
The method according to claim 5 , wherein the learning sequence d(n) corresponds to a learning sequence of SCH and TCH signals of GSM and DCS1800 radio communication systems.
Claim 8
Dependent Claim
81 words
The method according to claim 6 , wherein on a beacon frequency the demodulation of the signaling messages indicating the associated traffic frequencies and the identity of the base station is obtained by spatial filtering implemented by utilizing the learning sequence of the beacon frequency to modify a reception diagram and separate various signals received by forming reception holes in a direction of the jamming signals produced by other base stations and jammers external to a network of the base stations.
Claim 9
Dependent Claim
81 words
The method according to claim 5 , wherein on a beacon frequency the demodulation of the signaling messages indicating the associated traffic frequencies and the identity of the base station is obtained by spatial filtering implemented by utilizing the learning sequence of the beacon frequency to modify a reception diagram and separate various signals received by forming reception holes in a direction of the jamming signals produced by other base stations and jammers external to a network of the base stations.
Claim 10
Dependent Claim
81 words
The method according to claim 1 , wherein on a beacon frequency the demodulation of the signalling messages indicating the associated traffic frequencies and the identity of the base station is obtained by spatial filtering implemented by utilizing the learning sequence of the beacon frequency to modify a reception diagram and separate various signals received by forming reception holes in a direction of the jamming signals produced by other base stations and jammers external to a network of the base stations.
Claim 11
Dependent Claim
34 words
The method according to claim 9 , further comprising: implementing a spatial method of filtering by replica, by involving a path of highest power determined from the multipath synchronization, for matching the spatial filter.
Claim 12
Dependent Claim
34 words
The method according to claim 9 , further comprising: using a spatial method of filtering by filtered replica which makes it possible to involve a set of useful paths for matching the spatial filter.
Claim 13
Dependent Claim
20 words
The method according to claim 7 , further comprising: performing a one-dimensional equalization of the signals obtained by spatial filtering.
Claim 14
Independent Claim
155 words
A device for analyzing interference in a cellular radio communication system including beacon frequencies and traffic frequencies, comprising: a network of antennas coupled to a multipath receiver for the synchronous reception of signals received by each of the antennas; and a digital processing rig coupled to the multipath receiver and to a storage interface, wherein, to search on a specified analysis frequency while inside a cell for an origin of interference caused by neighboring cells, the device: performs a multipath synchronization on learning sequences of the beacon frequencies so as to determine a number of base stations using the specified analysis frequency as a beacon frequency, demodulates, after spatial filtering, identifiers of the base stations transmitting the beacon frequencies on which a synchronization has been made, and performs a multipath synchronization on learning sequences of traffic frequencies so as to determine a number of base stations using the specified analysis frequency as a traffic frequency.
Claim 15
Independent Claim
155 words
A device for analyzing interference in a cellular radio communication system including beacon frequencies and traffic frequencies, comprising: a network of antennas coupled to a multipath receiver for the synchronous reception of signals received by each of the antennas; and a digital processing rig coupled to the multipath receiver and to a storage interface, wherein, to search on a specified analysis frequency while inside a cell for an origin of interference caused by neighboring cells, the device: performs a multipath synchronization on learning sequences of the beacon frequencies so as to determine a number of base stations using the specified analysis frequency as a beacon frequency, demodulates, after spatial filtering, identifiers of the base stations transmitting the beacon frequencies on which a synchronization has been made, and performs a multipath synchronization on learning sequences of traffic frequencies so as to determine a number of base stations using the specified analysis frequency as a traffic frequency.
Claim 16
Dependent Claim
56 words
The device according to claim 13 , wherein the digital processing rig determines, in a GSM and DCS1800 network, on beacon-type channels, an identification word BSIC of the cells, which is obtained after demodulating SCH bursts, and determines the identity CI and the locating code LAC of each cell, which are obtained after demodulating BCCH bursts.
Claim 17
Dependent Claim
36 words
The device according to claim 13 , wherein the antennas of the network of antennas are spaced apart by a distance greater than 0.5 times the largest wavelength of the frequencies used in the radiocommunication system.
Claim 18
Dependent Claim
40 words
The device according to claim 13 , wherein the multipath receiver comprises a message extraction and decoding device coupled to a spatial filtering device by way of a one-dimensional equalization device comprising a processor programmed according to the Viterbi algorithm.
References Cited (Backward Citations)
US5812090A
Cited
US5752168A
Cited
US5848105A
Cited
US5930243A
Cited
US5870430A
Cited
US5937014A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-02-18 | 2005-08-20 | 2006-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-02-18 | 2009-08-20 | 2010-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-02-18 | 2013-08-20 | 2014-02-19 | $7700.00 | Window Closed / Lapsed |